| 摘要 |
A mass flow rate-controlling apparatus comprising a mass flow rate-detecting means 8 for detecting a mass flow rate to output a flow rate signal, and a flow rate-controlling valve mechanism 10 for changing a valve-opening degree in response to a valve-operating signal to control the mass flow rate in a flow path 6 for a fluid, and further comprising a means 44 for controlling the flow rate-controlling valve mechanism based on a flow rate-setting signal S 0 input from outside and a flow rate signal S 1 , the flow path being provided with a pressure-detecting means 42 for detecting the pressure of the fluid to output the detected pressure signal, so that the controlling means selectively switches a first control mode for controlling the mass flow rate based on the flow rate signal and the flow rate-setting signal without using the detected pressure signal, and a second control mode for controlling the mass flow rate based on the detected pressure signal, the flow rate signal and the flow rate-setting signal, based on a pressure variation obtained from the detected pressure signal.
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